Packing ring for pipe joints



April 23, 1935.

- l... A. CAMEROTA PACKING RING FOR PIPE JOINTS Filed Aug. lO, 1953 Cbmbf i, l *11.41F Q@ x M W Z 0 H l 03, J0 v mmbfw u 1%. m

Patented lpr. 233, i135 ry fr Machine Company, Florence., N. JJ., a cernporation of New lelrsey Application Aint It,

lill Claims.

This invention relates to packing rings for pipe joints or the like, andis particularly useful in its application to pipe joints characterizedby bell and spigot ends defniing an annular cavity within which thepacking ring is interposed. Heretofore many formsl of pipe joints of thebell-andspigot type have been used in which a packing ring ofsubstantially triangular or polygonal cross section is adapted to bewedged between the im adjoining pipe sections to serve as a sealingmember. Such pipe joints have for ,the most part been satisfactoryexcept where the joint is subjected to severe bending stresses tendingto cause relative flexure between the pipe sections, with consequentchanging cross sectional shape of the cavity Within which the packingring is compressed.

One difficulty that has been experienced with such pipe joints is thatthe compression of the packing ring causes the material thereof to flowor be extruded into the crevices between the elements which dei-lne thepacking ring cavity. Such cold flow of the material frequently causesits permanent distortion, destroying the capacity of the packing ring toresume its original shape. The portions of the ring which have thus beenextruded into the crevies of the joint are pinched or squeezed; andwithbending of the adjoining pipe sections, the extended portions areeventually cut and may be completely severed from the body of thepacking ring.

While attempts have been made to reinforce packing ringswith relativelystiff material at the critical surfaces which are subjected to apinching action, these attempts have not been altogether successful, forthe reinforcing elements, unless firmly embedded in will become detachedfrom the body; and where the reinforcing elements are disposed withinthe interior oi the packing ring body at a distance from the criticalsurfaces, the surface material will still be subjected to pinching andcutting.

Another diiculty that has been experienced with packing rings which arereinforced at the critical surfaces is that the reinforcements do notwithstand the corrosive or disintegrating eifect of oils, gases, acids,or the like in the pipe line or exteriorly thereoi, but deterioraterapidly in service.

Still another disadvantage of pipe joints constructed as heretofore withwedge shaped hollows for' the packings is that, incident to assemblingand compression of the packings', the two interfitted pipe sectionsbecome axially disaligned. As a consequence, there is metal to metalcontact of the pipe sections at one side of the joints with formation ofan imperfect seal and development of leaks at such regions.

The object of my present invention is to overcome the above reciteddiiiiculties by the provithe4 body of the ring,

ins, seen ne. (ci. etcii sion oi a novel form. of pipe joint with apacking ring which, by virtue of alfording a large rein forced surfaceor surfaces for distribution oi the load imposed upon it, will resistcold flow of the material at the crevices of the joint; which will notdisintegrate incident to repeated bending of the elements of the joint,but will form an eiec tive seal for a long period of service and whichwill insure accurate alignment as between the spigot and bell ends ofthe pipe.

Other more specific objects and advantages characteristic oi? myinvention will become apparent from the description hereinafter setforth of several embodiments or examples of the practice oi theinvention, having reference to the accompanying drawing.

Of the drawing:

Fig. I represents a cross sectionof a pipe joint constructed in themanner of my invention, and showing one form of packing ring compressedin the joint.

Fig. II represents an enlarged fragmentary cross section showing thepacking ring and its cavity before the joint is tightened.

Fig. IH represents a view similar' to Fig. II, but showing a modifiedform of packing ring after compression; d,

Fig. IV represents a similar view showing the modified form of packingring before' compression.

With reference to.,Fig. I of the drawing, there is shown at i the spigotor plain end of one pipe section, and there is shown at 2 the bell endof an adjoining pipe section. The bell end t? is enlarged or expanded atd and formed at the inside with a shoulder or seat t for abutment of thespigot end l of the other pipe section. The bell end 2 has at its mouthan annular cavity Ei adjacent to and surounding a. portion of the outersurface of the spigot end Il, the said cavity being rounded at thebottom as at 5a. bell end 2 terminates in anannular flange t engaged bylugs i on the ends of clamp bolts t.

Extending around the spigot end i there is a clamping member 9 in theform of 'a ring having a pendant flange portion l t projecting in thedirection of the longitudinal axis of the joint which is adapted toenter between the flange li of the bell member 2 and the outer surfaceof the spigot member i, the edge of the flange i@ being concaved as atlila. The clamping ring 9 is provided with a series of spaced holesJ ilfor the reception of the bolts which have threaded ends with nuts i2applied thereto. When the bolts 8 are inserted through the holes ii ofthe clamping ring 9 by tightening the nuts it, the clamping ring 9 isforced in the direction of the longitudinal axis of the joint toward themouth of the bell member 2 into the annular cavity 5.

It will be observed that the annular cavity 5 4o Moreover, the

deiinedby the spigot member i, the bell member 2 and the clamping ring 9is relatively wide,

, straight sided, and 'rounded top and bottom, and

uninterrupted except at three regions where there are crevices foreasement oi the joint, one such crevice at the base of the cavity beingdesignated at A, and the two crevices at the inner and outer side of theportion i@ of the clamping ring being designated, respectively, at b andc. While the cross sectional shape of. the armular cavity 5 admits ofconsiderable variation, it is desirable to avoid sharp corners and tohave a dat wall as indicated at l opposed to and substantially,

parallel with the outer surface oi the spigot member i.

In Figsl and lli oi the drawing, there is represented one forni oipacking ring D embodying my invention, the ring being shown in Fig. I inthe shape which it assuma after compression in the pipe joint. Thepacking ring D is substantially of oval cross sectional shaM e, althoughits exterior shape, as well as the shape of the cavity within which itis inserted, may be varied to considerable extent provided that sharpangles or corners are avoided.' The body i5 of the packing ring D is ofresilient or yielding material, such as rubber, and has incorporatedtherewith at opposite ends reinforcing elements it which closely followthe surface contour oi the curved ends ci the packing ring. Thereinforcing elements it may be impregnated with the material of the bodyportion or joined thereto with a iirm bond. Preferably the body iti andthe reinforcing elements l5 are covered with a relatively thin layer ofa suitable material as indicated at il, which is immune corrosion ordisintegra-w tion by oils, gases, acids or the lilre in the pipe line orexteriorly thereof. The material of which the thin protective coveringil is made will necessarily depend upon the nature of the huid in thepipe line, but :for most purposes the material known commercially asthioirol has been found satisfactory. Each reinforcing element it is ofarched cross sectional shape, as represented in Fig. il, and issuinciently stiii? to avoid sharp distortion at any point when thepacking ring D is subjected to endwi comprmion. Layers of canvas may beemployed to maire up the reinforcing elements, or wire mesh fabric orother material of the required stiffness may also be utilized. Thematerial, however, should be of such character that the reinorcingelements it ex to a certain extent when the packing ring is placed undercompression, with resulting expansion of the resilient body i5 at thesides of the packing ring.

When the packing ring D is compressed, as represented in Fig. i, it willbe observed that the reinforcing elements it are gradually flattenedwithout sharp distortion at the crevices a, b and c, and that thereinforcing elements bridge the crevices in such manner that there is noopportunity for the body i5 of resilient material to be sharplydistorted at these regions. Moreover, the effect of tightening the nutsi2 on the bolts 8 is to draw the clampingring t into the mouth of thebell end 2 and to expand the resilient body i 5 in a direction towardthe outer surface of the spigot member i and toward the opposed wall itof the bell member 2, forming a tight seal at the sides of thepackingring. By distribution of the compression load over acomparatively large area of the reinforcements it, it will be seen thatcold flow ofthe packing is effectively prevented.

In Figs. Hl and lV there is represented a modi- :tenaces ned form ofpacking ring E having a body portion i5 of resilient material, such asrubber, and having pairs of arched reinforcing elements I8 at itsopposite curved ends. In this-example of the practice of my invention,at each end of the packing ring E two semi-circular or archedreinforcing elements are joined together to form a. substantiallycylindric reinforcement when the packing ring is in its natural shape,and the interior of each cylinder is filled with the resilient body ma.aterial, 'as indicated at I9. Incident to compression of the packing ringE, the reinforcing elements i'are attened so that each element -assumesa substantially elliptic shape. The resilient body i5 is also in thiscase expanded laterally when the packing ring is compressed against theouter surface of the spigot member I and against the iiat wall I4 of thebell Amember 2. Thus, here again, there is no sharp distortion of thereinforcing elements i8 at the regions where the crevices a, b and carebridged. As shown, the f packing ring E is provided with a thinprotective covering 2 of a materiallike that described in connectionwith the iirst embodiment of my invention.

It will be observed that the packing rings here- .in described avoid thediiculties heretofore experienced` with wedge shaped packing rings whichare forced into narrow crevices incident to the tightening up of a. pipejoint, and which are subjected to a cutting action incident to bendingof the elements or the joint. Furthermore, it will be observed that thepacking ring of my invention is self-seating in the cavity within whichit is inserted in the sense that no particular care need beexercised asto the initial position of the packing ring 'when inserted. While thepacking rings herein described are free of the disadvantagescharacteristic of older forms 'of packing rings, they nevertheless serveto effect a tight seal between the elements of a pipe joint, and theyassist in rendering the joint flexible in character. Due to thehereinbeore described novel construction of the bell end oi the pipe andby virtue of the exact conformity of the preformed gaskets packing tothe straight sided annular cavity formed jointly with the spigot end,the two joint parts are of necesisty accurately aligned incident toassembling. In other words, the packing is self centering and thusoperates as a means to initially align the .pipe ends and to so maintainthem subsequently with preclusion of the possibility of leakage in thejoint.

While I have described several examples of the practice of my inventionwith reference to one specific form of pipe joint and two specific formsof packing rings embraced thereby, it is to be vunderstood that variouschanges may be made in the shape and material of the packingl ring andits cavity; and that the packing ring of this invention may be employedto advantage for other purposes than for pipe joints all withoutdeparting from the spirit of my invention as defined in the annexedclaims.

Having thus described my invention, I claim:

1. A packing for pipe joints or the like comprising a ring having a bodyof yielding material,

and having an arched reinforcing element closely.

following the exterior contour of the ring near a. portion of itssurface and impregnated with the body material in such manner as to beilrml'y bonded thereto, said reinforcing element being of such stiffnessas to resist sharp distortion and oi such flexibility that itwillgradually ilatten when the ring is placed under compression witl`inci- Cil dental expansion of the yielding bodfyf'lat the nonreinforcedpbrtions of its surface.

y2. A packing for pipe joints or the like ccmprising a ring ofsubstantially oval cross section having a body of resilient material andhaving incurved arched reinforcing elements embedded. within andinseparably bonded to said body at opposite ends thereof, saidreinforcing elements being of such exibility that whenvthe ring is-placed under endwise compression 'they will gradually flatten withavoidance of sharp distortion and with incidental expansion of the bodymaterial at the sides of the ring.

3. A packing for pipe joints or the like comprising a ring of`substantially oval cross section having a body of resilient materialand havingarched reinforcing elements inseparably bonded to and embeddedwith said body adjacent opposite curved ends thereof, said reinforcingelements following the surface contour of said curved ends and being ofsuch flexibility that when the ring is placed under endwise compressionthey will gradually flatten with avoidance of. sharp bending and withincidental expansion of the body material 'at the sides of the ring.

t. A packing for pipe joints or the like comprising a ring having a bodyof resilient material, and having arched reinforcing elements embeddedtherein at opposite ends and closely following the surface contour ofthe ring at said ends, said reinforcing elements being of suchflexibility that they will gradually flatten when the ring is placedunder compression, and a thin corrosive resistant protective covering ofplastic material surrounding the ends of said packing in close proximityto said reinforcing elements.

5..A packing for pipe joints or. the like comprising a ring having abody of resilient material and having alsmoothly curved reinforcingelement embedded therein and closely following the surface contour ofthe ring at one end thereof, said reinforcing elementl being of suchstiffness as to resist sharp distortion and being inseparably bonded tothe body material so as to flex in the manner of an elliptic fspringwhen the ring is placed under varying degrees of endwise compression.

6. A packing for pipe joints or the like comprising a ring ofsubstantially oval cross section having a body of resilient material andhaving reinforcing elements of substantially cylindric cross sectionalform embedded'within said body and bonded thereto at its opposite curvedends and centrally lled with the resilient material, said reinforcingelements following the surface contour of said curved ejnds and being ofsuch flexibility that they will gradually flatten when the ring isplaced under endwise compression.

7. In a pipe joint including bell and spigot ends anda clamp memberdefining an annular cavity, a packing ring in said cavity comprising abody of yielding material havingan arched reinforcing element closelyfollowing the exterior contour of the ring near a portion of its surfaceand impregnated with the body material in such manner as to be firmlybonded thereto, said reinforcing element bridging the crevices of saidcavity between said bell and spigot ends and said clamp member, and saidreinforcing element being adapted to flex when the clamp member istightened with incidental expansion of the yielding incassa bodyduid-tight against the walls of said bell and spigot members.

8. In a pipe joint including bell and spigot ends and a clamp memberdefining an annular cavity, a packing in said cavity comprising a bodyof resilient material having an arched reinforcing e ement incorporatedtherein and serving to bridge the crevicesy of said cavity between saidbell and spigot endsand said clamp member, said reinforcing elementbeing adapted to ex in the manner oi' an elliptic spring when the clampmember is tightened with incidental expansion of the resilient bodyagainst the walls of said bell and spigot members. y

9. In a pipe joint including bell and spigot ends and a clamp memberdening an annular cavity, a packing in said cavity comprising a ring ofoval cross section having a body of resilient material and havingsmoothly curved reinforcing elements embedded therein at opposite endsand bridging the crevices of said cavity between said bell and spigotends and said clamp member, said reinforcing elements being adapted toflex when the clamp member is tightened, with incidental expansion ofthe non-reinforced sides of said packing ring against the walls of saidbell and spigot members, and said packing ring having a relatively thincorrosion-resistive protective covering of plastic material in closeproximity to said reinforcing elements at the crevices of the cavity andrestrained by said elements against ex- -trusion into said crevices.

10. In a pipe joint including bell and spigot ends and a clamp memberdefining a relatively wide annular cavity with parallely vertical sidesand rounded top and bottom, a packing in said cavity comprising a ringof corresponding cross section having a straight sided body of resilientmaterial and having smoothly curved reinforcing elements incorporatedtherewith at opposite ends to bridge the crevices of `said cavitybetween said bell and spigot ends and said clamp member, saidreinforcing elements being of such stiffness as to resist sharpdistortion and being adapted to flex when the clamp member is tightenedwith incidental expansion of the yielding vbody fluid tight against thewalls of said bell and spigot members,

and said reinforcing-elements being impregnated with the body materialso as to partake of its tendency to assume its original shape.

11. In a pipe joint including bell and spigot members and a clamp memberdefining a relatively wide annular cavity with parallel vertical sidesand rounded top and bottom, a packing in said cavity comprising a ringof corresponding cross section with a straight sided body of resilientmaterial, and having reinforcing elements of substantially cylindriccross sectional form embedded in said body and centrally filled with theresilient material, with their outer surfaces bridging the crevicesbetween said bell and spigot ends and said clamp member, saidreinforcing elements being adapted to flex when the clamp member istightened, without sharp bending at the regions of said crevices andwith incidental expansion of the yielding body uid tight against thewalls of said bell and spigot members, and said reinforcing elementsbeing impregnated with the body material so as to partake of itstendency to assume its original shape.

DES A. CAMEROTA.

